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The Spectrum Project, Part II

The Spectrum Project, Part I

By Bob Green

Commemorating the Oct 31, 2003 “wake” for the HP 3000, Robelle are devoting our NewsWire column to some history. Our story of the original 16-bit HP 3000 (1972-1976) is told on our Web site.

After initial development, the HP 3000 grew and prospered. From 1974 to 1984, HP continued to produce more powerful 3000 hardware running more capable software. Each new model was compatible with the previous version and a joy to install.

But the pressure was on to switch to a 32-bit architecture, as other manufacturers were doing. So HP announced a radical change: a new 32-bit hardware for the 3000. The project was code-named Spectrum. As a 3000 consumer and 3000 vendor, Robelle was excited and concerned about the prospect of a new hardware architecture. Certainly it would be wonderful to have more powerful processors, but what about the disruption to our steady incremental, risk-less progress?

The first notice we took of the Spectrum appeared in our December 1984 customer newsletter, with continuing news to follow for the next four years (my retrospective comments are included as “In Retrospect”).

December 12, 1984

The first Spectrum machine will be an upgrade for the Series 68. Other size models will follow soon after, since HP is working on different Spectrum CPUs in three divisions at once (in the past, all 3000 CPUs came out of one division). This first Spectrum can be expected in the first half of 1986.

In Retrospect: Please make a note of that 1986 promised delivery date, and remember that HP faced serious competition from DEC and others. Customers who loved the 3000, but had outgrown the power of the system, were demanding more capable models.

Spectrum is based on the RISC concept, modified by HP Labs. RISC stands for Reduced Instruction Set Computing. Such a computer has no micro code, only a small number of key instructions implemented in very fast logic. The original Berkeley RISC machine had only 16 instructions. Spectrum has more than 16, but not many more. HP selected the instructions for the fast base set by studying typical application mixes on the existing HP machines. Other functions will be done via subroutines or co-processors (e.g., a floating-point processor, an array processor, or a database processor).

In Retrospect: The actual number of instructions in the Spectrum turned out to be about 130, not 16, but they were all simple enough to run in a single clock cycle. HP was the first computer company to go with the RISC philosophy and the only major one to risk the firm by converting all their computer models, both technical and commercial, to a single RISC design.

June 11, 1985

HP’s new Spectrum machine will have both Native-Mode software and 3000 software. The first Spectrum machine to be released will have 3-10 times more computing power than a 68, about 8-10 MIPS in Native Mode. Programs copied straight across will run about twice as fast as on a 68, and those that can be recompiled in Native Mode should run 6-8 times faster. Much of MPE, including the disk portion of the file system, has been recoded in Native Mode. Since most programs spend most of their time within MPE, even programs running in emulation mode should show good performance (unless they are compute-bound).

In Retrospect: The expectations were building in our minds: these machines would be much faster than our current models!

Spectrum will use much of the new operating system software that had been written for Vision, which saves a great deal of development time. Spectrum will use 32-bit data paths and will have a 64-bit address space. Forty Spectrum machines have been built and delivered for internal programming, but product announcement is not likely before 1986.

In Retrospect: Vision was an alternative 32-bit computer project at HP, using traditional technology, which was cancelled to make way for the RISC design from HP Labs. Invoking Vision re-assured us that this project is possible, that progress is being made. It was now six months after the first announcement of the project.

August 16, 1985

According to an HP Roundtable reported in the MARUG newsletter, “Most of what is printed about Spectrum is not to be trusted. Spectrum will be introduced at the end of 1985 and delivered in Spring 1986. There are 40-50 prototypes running in the lab and the project team consists of 700-800 engineers. HP will co-introduce a commercial version and a technical version with the commercial version fine-tuned to handle many interactive users, transaction processing, IMAGE access, and the technical version will be structured for computational programs, engineering applications, and factory automation. HP will eventually offer a choice of MPE and Unix. Most software will be available on Spectrum at introduction time and over time all software will be available.”

In Retrospect: HP tried to dispel rumors, but still predicted 1986 for delivery. HP would produce two Spectrum lines: the Unix line for technical users and the MPE line for commercial users, using the exact same hardware.

“The following describes what will be required to convert – Least: restore files and IMAGE databases as they are and run. Next: recompile programs in native mode. Next: change over to new IMAGE database system. Next: change source code to take advantage of RISC.” Robelle Prediction: Spring 1986 for a Spectrum that will reliably run existing MPE applications is not an attainable release date.

In Retrospect: The new relational HPIMAGE database mentioned here was cancelled much later in the project, after a brief encounter with end-users. I don’t remember much about HPIMAGE, except that a lot of work went into it and it didn’t succeed as hoped. TurboIMAGE ended up as the database of choice on the Spectrum. Without any inside information, but based just on past experience and common sense, Robelle tried to inject some caution about the 1986 release date. During the original traumatic HP 3000 project, Dave Packard “sent a memo to the HP 3000 team,” according to Chris Edler. “It was only two lines long and said, essentially, that they would never again announce a product that did not then currently meet specifications.” The division listened for over 10 years, but eventually, people forget….

September 20, 1985

From a Spring 1985 UK conference: Most existing peripherals will be supported and it will be possible to use networking software to link existing model HP 3000s to Spectrum, with the exception of Series II/III and 30/33. These would need a Series 37 or other current range machine to act as a gateway to Spectrum.

From an HP press release: “100 prototype models were already being used internally for system development as of April 1985.”
HPE, the new operating system for the commercial Spectrum is a superset of MPE. It will have two modes of operation: Execute mode (HP 3000) and Native Mode. The switch between the two will be made on a procedure call, but there will be some programming work needed to translate parameters when switching.

In Retrospect: Execute mode was eventually called Compatibility Mode and switching between modes turned out to be major CPU bottleneck in the new system, albeit one that would be removed over time.

The Spectrum is rumored at this time to provide 32 general-purpose registers to the user program and a virtual data space of 2 billion bytes.

December 30, 1985

From Gerry Wade of HP: The name of the Spectrum machine, when it comes out, will not be Spectrum. Another company already has that name. Spectrum will use the IEEE standard for floating-point arithmetic and will also support the HP 3000 floating point. Each data file will have a flag attached to it that tells which type of floating-point data it contains (the formats are not the same).

In Retrospect: The file flag idea never happened, although the TurboIMAGE database did introduce a new data type to distinguish IEEE floating point. Information on implementation details is starting to flow, which helps us believe that the project is on schedule and likely to deliver the more powerful servers we desire.

June 16, 1986

In reporting on Joel Birnbaum’s Spectrum presentation, the HP Chronicle had these observations: “Comparisons with Amdahl and DEC mainframes in slides showed areas where the Spectrum computers topped the larger machines’ benchmarks. ‘Even with un-tuned operating systems software, it’s significantly superior to the VAX 8600,’ Birnbaum said.”

In Retrospect: Joel was the HP Labs leader who was the sparkplug of the RISC project, building on research that he had done previously at IBM. In retrospect, we can see that Joel was talking about the performance and delivery of the UNIX Spectrum, not the MPE version, but customers took this as a promise of vast performance improvements in the very near future. It was now past Spring 1986 and the promised new 3000 machines were nowhere in sight. In fact, HP has not yet announced the new models and pricing. This was the first slippage in the project, barely noticed at the time.

July 20, 1986

Many people have been asking, “What is Robelle doing about Spectrum?” HP has invited us to join its Fast Start program for third parties and we have agreed. This program gives us pre-release access to Spectrum information and actual systems. We have visited Cupertino and run our software on the new machines. We are confident that all of our products will operate properly at the time that Spectrum is officially released.”

In Retrospect: Since Suprtool and Qedit were essential to the large 3000 customers that HP was targeting, HP asked Robelle to start porting and testing our products on the new systems. But to do that, we had to sign a Non-Disclosure Agreement, the most draconian one we had ever seen. We used careful wording in our announcement above. From this date on, until years later, we could not tell our customers anything useful about the new machines. HP was especially sensitive about their reliability and performance.

When we arrived in Cupertino to do our first testing, we found the prototype Spectrum systems crashing every few minutes and running slower than our tiny system 37. We were appalled. Nothing in HP’s public statements had prepared us for the state of the project. I had personally gone through a similar situation with the original 3000 in 1972-74, and I wondered if upper management at HP knew how terrible things were. I thought about talking to them, but our NDA also prohibited us from talking to anyone at HP.

The Unix versions of Spectrum, on the other hand, seemed to be humming along nicely, showing that it was not a hardware problem.

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